Homoleptic copper(I) and silver(I) complexes with o-phenylene-backboned bis(thioethers), bis(selenoethers), and bis(telluroethers): Synthesis, multinuclear NMR studies, and crystal structures of [Cu{o-C6H4(SeMe)(2)}(2)]PF6, [Cu{o-C6H4(TeMe)(2)}(2)]PF6, and [Ag-n{mu-o-C6H4(SeMe)(2)}(n){o-C6H4(SeMe)(2)}(n)][BF4](n)center dot nCH(2)Cl(2)

Homoleptic copper(I) and silver(I) complexes [M(L-L)(2)]X (M = Cu, X = PF6; M = Ag, X = BF4; L-L = o-C6H4(EMe)(2); E = S, Se, Te) have been prepared and characterized by analysis, FAB mass spectrometry, and multinuclear NMR spectroscopy (H-1, Se-77, Te-125, Cu-63, Ag-109). Variable-temperature NMR studies have been used to probe various exchange processes occurring in solution. Single-crystal X-ray structural studies show that the Cu(I) complexes Cu{o-C6H4(SeMe)(2)}(2)]PF6 [trigonal, a 13.29(2), c = 65.97(2) Angstrom, R(3) over barc$, Z = 18] and [Cu(o-C6H4(TeMe)(2)}(2)]PF6 [trigonal, a = 13.632(6) Angstrom, c = 67.983(4) Angstrom, R(3) over barc$, Z = 18] are isostructural and exist as mononuclear species with chelating bis(seleno- and bis(telluroethers), respectively, whereas the single-crystal structure of [Ag{o-C6H4(SeMe)(2)}(2)]BF4 [monoclinic, a = 19.273(7) Angstrom, b = 11.927(3) Angstrom, c = 20.405(6) Angstrom, beta = 90.42(3)degrees, P2(1)/c, Z = 4] comprises infinite chains of [Ag-n{mu-o-C6H4(SeMe)(2)}(n){o-C6H4(SeMe)(2)}(n)](n+), discrete BF4-, anions and CH2Cl2 solvent molecules. The o-C6H4(SeMe)(2) ligands in the latter exist as a mixture of invertomers within the infinite chains; the chelating ones adopt the meso arrangement while the bridging ones occur as the DL form. This is the first structurally characterized complex involving a bridging o-phenylene group 16 donor ligand and the first case of both invertomers occurring in a single complex.